SimpleBlobDetector Blob計數

Question

如何確定在Python 2.7中使用SimpleBlobDetector發現的斑點數量？我有示例代碼查找和標記圖像中的斑點，但也需要知道有多少斑點匹配我的參數。

#!/usr/bin/python 

# Standard imports 
import cv2 
import numpy as np; 
from matplotlib import pyplot as plt 

# Read image 
im = cv2.imread("blob.jpg") 

# Setup SimpleBlobDetector parameters. 
params = cv2.SimpleBlobDetector_Params() 

# Change thresholds 
params.minThreshold = 10 
params.maxThreshold = 200 

# Filter by Area. 
params.filterByArea = True 
params.minArea = 15 

# Filter by Circularity 
params.filterByCircularity = True 
params.minCircularity = 0.1 

# Filter by Convexity 
params.filterByConvexity = True 
params.minConvexity = 0.87 

# Filter by Inertia 
params.filterByInertia = True 
params.minInertiaRatio = 0.01 

# Create a detector with the parameters 
detector = cv2.SimpleBlobDetector(params) 

# Detect blobs. 
keypoints = detector.detect(im) 

# Draw detected blobs as red circles. 
# cv2.DRAW_MATCHES_FLAGS_DRAW_RICH_KEYPOINTS ensures 
# the size of the circle corresponds to the size of blob 

im_with_keypoints = cv2.drawKeypoints(im, keypoints, np.array([]), (255,0,0), cv2.DRAW_MATCHES_FLAGS_DRAW_RICH_KEYPOINTS 

titles = ['Blobs Detected'] 
images = [im_with_keypoints] 


for i in xrange(1):  
    plt.subplot(1,1,i+1), plt.imshow(images[i],'gray') 
    plt.title(titles[i]) 
    plt.xticks([]), plt.yticks([]) # to hide tick values on X and Y axis  
plt.show() 

Answer 1

你只需要

nblobs = len(keypoints)